only after a mob showed up at his company's door and demanded it.
THAT is the real issue here, not wether or not his contribution anybody agreed with. He was an employee in good standing of the company TWO YEARS AGO when he made these donations and for the two years after. He was promoted to a new position. The Internet got wind of his previous personal donations and basically lynched him for an unpopular opinion.
On one hand, CEOs are "rockstar" employees.... they set the tone, direction, and "opinions" of the company based on their personal experiences. So their private opinions matter significantly more than regular employees. On the other hand, the Mozilla Board of Directors should have hit exactly what this article is pointing out head on, right out of the gate. They should have explained up front, they knew about his personal donation, and due to his business at the company they were deciding to promote him. They could have added something about the Mozilla corporation still being committed to "everybody getting along" or something like that. They should never have entertained the idea in public that they possibly would reconsider their decision just because a mob showed up.